1. Field of the Invention
The present invention relates to a display substrate, a method of manufacturing a display substrate and a liquid crystal display (“LCD”) device having the display substrate. More particularly, the present invention relates to a display substrate having substantially improved display quality, a method of manufacturing the display substrate, and an LCD device having the display substrate.
2. Description of the Related Art
Generally, a patterned vertical alignment (“PVA”) mode and, more particularly, a mobile PVA (“mPVA”) mode, display device, utilized in a small- or medium-size screen, applies a circular polarization mode having advantages over other modes in terms of transmissivity, for example. Alternatively, a linear polarization mode having advantages over other modes in terms of visibility and contrast ratio, for example, may be applied.
In the mPVA mode display device, slit portions are formed in both a common electrode of a color filter substrate as well as a pixel electrode of an array substrate to form a multi-domain structure for improving a viewing angle of the display device.
In the mPVA mode display device, a size of a pixel is small relative to other types of display devices, and an aperture ratio of the pixel is higher. Moreover, a director of liquid crystal typically has a maximum angle of about 45 degrees with respect to a polarization axis of a polarizer. As a result, however, a conventional compensation film cannot remove light leakage from a side surface of the mPVA mode display device. Accordingly, off-axis image quality the mPVA mode display device needs to be improved.
A polymer-stabilized vertical alignment (“PSVA”) mode, in which liquid crystal molecules are controlled by a micro-slit pixel structure without patterning a common electrode of an upper substrate, has been developed. A stability of a domain may be reduced, however, since the common electrode is not patterned on the upper substrate. In attempts to solve this problem, a small amount of a reactive mesogen is added during a manufacturing process of a panel of the display device, and the mesogen moves in a same direction as the liquid crystal molecules during the manufacturing process. After the panel is manufactured, ultraviolet rays are irradiated onto the panel and the reactive mesogens are thereby polymerized. As a result, a direction is applied to the liquid crystal.
However, transmissivity is substantially reduced during the manufacturing process, due to the micro-slit pixel structure and the line polarized polarizer.